In electronic apparatuses, for example, feature phones, smartphones, and computers, flexible printed circuits (hereinafter, referred to as FPCs) on which electronic components can be mounted have been used to achieve compactness and weight reduction. As the electronic components, for example, semiconductor chips and connectors can be assumed.
Regarding the FPCs, it has been requested that the electronic components be mounted at high density with flexibility maintained (high-density packaging), and the degree of freedom of circuit design be improved (circuit design liberalization).
Incidentally, in the FPCs, reinforcing plates are provided at portions, the mechanical strength of which needs to be increased. In conventional FPCs, it has been impossible to mount electronic components on the portions at which the reinforcing plates are provided. Thus, there has been a certain limit on the high-density packaging and the circuit design liberalization.